---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Mon 04/04/11: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:55 AM - Drop in Oil Pressure (Hugh McKay) 2. 10:53 AM - Re: Drop in Oil Pressure (FLYaDIVE) 3. 06:16 PM - Re: Drop in Oil Pressure (Roger Lee) 4. 07:43 PM - Questions about radiator & duct tape on a 582 (TheWanderingWench) 5. 08:23 PM - Re: Questions about radiator & duct tape on a 582 (Bob Comperini) 6. 08:50 PM - Re: Questions about radiator & duct tape on a 582 (TheWanderingWench) ________________________________ Message 1 _____________________________________ Time: 09:55:37 AM PST US From: "Hugh McKay" Subject: RotaxEngines-List: Drop in Oil Pressure My 912 UL oil pressure normally runs right at 4 bar (58.8 psi). Recently I have noticed the pressure has dropped to 3 bar (44.1 psi), a drop of 25%. Don=99t understand why? The only thing different in my operation is two weeks ago I had to make a three hour flight to Macon, GA and then returned to N92. While in Macon I put 10 gallons of 100LL in my main tank (the only fuel available). This is the first time I have had to use 100LL in the 430 hours I have flown the plane. I noticed the drop in oil pressure a few days after that flight. Any reasonable explanation for this drop in pressure? Hugh G. McKay III, P.E. Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 Ph. 704-661-8271 Fax 704-483-5466 email hgmckay@bellsouth.net http://www.wwegeo.com ________________________________ Message 2 _____________________________________ Time: 10:53:35 AM PST US Subject: Re: RotaxEngines-List: Drop in Oil Pressure From: FLYaDIVE Hugh: With the information given there is NO reason why you should see a pressure drop from changing to AvGas for a few hours. Do you have EGT & CHT gages? If so what were their readings? You may see a drop in EGT due to the higher octane, but that would be very slight. CHT... May also have come down 5 degrees F. Are there any LEAKS? A long flight will have steady high temps and steady vibration - Putting this together may just develop a small leak. Are there any CLOGS (dirty oil)? Dirty oil looses viscosity and even more at temps. A loss here will show a s a loss in oil pressure. How HOT is your oil? As oil increases in temperature BEYOND normal the oil thins. This is shown as a DECREASE in oil pressure and an INCREASE in oil temperature. Being that AvGas has a high lead content and engines that use it regularly have shown an increase in blow-by. This blow-by surely will weaken the qualities of the oil and can show early signs as a DECREASE in oil pressure and an INCREASE in oil temperature. OK - That's all for now... You will have to give more information and see what time shows. Barry On Mon, Apr 4, 2011 at 9:02 AM, Hugh McKay wrote: > My 912 UL oil pressure normally runs right at 4 bar (58.8 psi). Recentl y > I have noticed the pressure has dropped to 3 bar (44.1 psi), a drop of 25 %. > Don=92t understand why? The only thing different in my operation is two w eeks > ago I had to make a three hour flight to Macon, GA and then returned to N 92. > While in Macon I put 10 gallons of 100LL in my main tank (the only fuel > available). This is the first time I have had to use 100LL in the 430 hou rs > I have flown the plane. I noticed the drop in oil pressure a few days aft er > that flight. Any reasonable explanation for this drop in pressure? > > Hugh G. McKay III, P.E. > Senior Consultant > Worldwide Engineering Inc. > 4090 North NC Hwy. 16 > Denver, NC 28037 > > Ph. 704-661-8271 > Fax 704-483-5466 > email hgmckay@bellsouth.net > http://www.wwegeo.com > ________________________________ Message 3 _____________________________________ Time: 06:16:16 PM PST US Subject: RotaxEngines-List: Re: Drop in Oil Pressure From: "Roger Lee" Hi Hugh, If the pressure is steady then it shouldn't be a ground or wiring issue. The oil pressure senders are notorious for going out and they do many times go out slowly by dropping pressure. The sender is a rheostat type so vibration or heat over time can cause them to go bad. I would be willing to bet you don't have a real oil problem, but just a bad reading. You can pick up a sender from Lockwood for around $36 and try it. The other thing may help is put in the new Rotax oil pressure regulator cone and taller plug screw if you haven't done so already. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Repair Center Home 520-574-1080 TRY HOME FIRST Cell 520-349-7056 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=336107#336107 ________________________________ Message 4 _____________________________________ Time: 07:43:52 PM PST US From: TheWanderingWench Subject: RotaxEngines-List: Questions about radiator & duct tape on a 582 I have a 2-piece radiator on my upright-mounted Rotax 582. All of the pilot s at my airfield "regulate" the water temps using duct tape around the radi ators in the winter (covering approximately 1/2-3/4 of each radiator) and t aking the duct tape off in the summer. We fly at altitudes of approximately 1000-3000' MSL. I will be flying to Oshkosh this summer and will be flying at altitudes of up to 11,000' across Wyoming - yet on-the-ground temps will be pretty warm. It makes me nervous to think of using this duct tape system.- What other options do I have? Arty Trost Sandy, Oregon www.LessonsFromTheEdge.com/uladventure2009.htm =0A =0A"Life's a daring adventure or nothing" =0A Helen Keller =0A =0A"I refuse to tip toe through life just to arrive safely at death." ________________________________ Message 5 _____________________________________ Time: 08:23:40 PM PST US From: Bob Comperini Subject: Re: RotaxEngines-List: Questions about radiator & duct tape on a 582 > >What other options do I have? Do you have a thermostat on the engine? Not sure you'll need anything else besides that, but there are some people making louver systems for some radiator setups. here's one: http://www.theultralightplace.com/new_page_8.htm How about mixture control? -- Bob Comperini e-mail: bob@fly-ul.com WWW: http://www.fly-ul.com ________________________________ Message 6 _____________________________________ Time: 08:50:16 PM PST US From: TheWanderingWench Subject: Re: RotaxEngines-List: Questions about radiator & duct tape on a 582 Nope - no thermostat or mixture control. I guess I should look into both. Thanks, Bob - I should have guessed that you'd be able to respond to this q uestion. Arty --- On Mon, 4/4/11, Bob Comperini wrote: >What other options do I have? Do you have a thermostat on the engine? Not sure you'll need anything else besides that, but there are some people making louver systems for some radiator setups. here's one: http://www.theu ltralightplace.com/new_page_8.htm How about mixture control? -- Bob Comperini e-mail: bob@fly-ul.com WWW: http://www.fly-ul.com le, List Admin. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.